FERMENTATION 295 



a thistle does to its seed. ISTo wonder then, with analogies 

 so obvious and so striking, that the conviction is spread- 

 ing and growing daily in strength, that reproductive para- 

 sitic life is at the root of epidemic disease — that living 

 ferments finding lodgment in the body increase there and 

 multiply, directly ruining the tissue on which they sub- 

 sist, or destroying life indirectly by the generation of 

 poisonous compounds within the body. This conclusion, 

 which comes to us with a presumption almost amounting 

 to demonstration, is clinched by the fact that virulently 

 infective diseases have been discovered with which living 

 organisms are as closely and as indissolubly asLOciated as 

 the growth of Torula is with the fermentation of beer. 



And here, if you will permit me, I would utter a word 

 of warning to well-meaning people. We have now reached 

 a phase of this question when it is of the very last impor- 

 tance that light should once for all be thrown upon the 

 manner in which contagious and infectious diseases take 

 root and spread. To this end the action of various fer- 

 ments upon the organs and tissues of the living body must 

 be studied ; the habitat of each special organism concerned 

 in the production of each specific disease must be deter- 

 mined, and the mode by which its germs are spread 

 abroad as sources of further infection. It is only by such 

 rigidly accurate inquiries that we can obtain final and 

 complete mastery over these destroyers. Hence, while 

 abhorring cruelty of all kinds, while shrinking sympa- 

 thetically from all animal suffering — suffering which my 

 own pursuits never call upon me to inflict — an unbiased 

 survey of the field of research now opening out before 

 the physiologist causes me to conclude that no greater 

 calamity could befall the human race than the stoppage 



